Method of lasting shoes



. July 25g 1933- .L s. KAMBoRlAN v 19,919,659

mamon QFLASTING SHOES y A lllllllfll/ /l/ A Filed oct. 15. l19:51

Patentedl July 25, 1933 UNITED STATES PATENT OFFICE:

JACOB S. KAMBORIAN, 0F WEST NEWTON, MASSACHUSETTS, ASSIGNOR T0 NORTHERN MACHINE C0., INC., OF BOSTON, MASSACHUSETTS, A CORPORATION 0F MASSACHU- SETTS METHOD OF LASTING SHOES Application illed October 15, 1931.

This invention pertains to the manufacture of footwear, and-relates more particularly to devices adjunctive to the shoe lasting process and to a novel -process of last- 1n In my copending application Serial No. 515,921, filed February 16, 1931, I have'disclosed one desirable method of lasting shoes in which the material of the upper at the end portion ofthe shoe is effectively `flattened and leveled and is permanently secured 'rin place by means of adhesive instead of tacks, staples, or other independ being depended upon to supply the necessary adhesive for uniting the shoe parts,

but for some kinds of shoe this overlap of the toe box flange may be undesirable and,

furthermore, the operation of preparing the toe box, including the application and predrying of the cement, adds materially to the cost of the shoe,-the latter objection,l

applying with equal force to the application of the cement directly to the edge of the upper, sug estad/,as an alternative procedure in my a oresaid application. I have also previously accomplished desirable results by applying-a hot Huid adhesive of uick setting character to the opposed suraces of the shoe parts at the toe or heel to hold them in lasted position, but while ef' fective, this method is objected to by some operators by reason of the difficulty involved in applying the fluid adhesive to the shoe bottom without daubing the exposed portions of the upper.

In accordance with the present invention I avoid all of the features ofmy prior Serial No. 568,922.

processes whiohmight by any/possibility be considered as disadvantageous, while retaining their des'irab'le characteristics, so that my present improved lasting process 1s thoroughly practical from the commerc1al standpoint, while at the same time further reducing the cost of shoe manufactiire. -In the accompanying drawing I have indicated certain desirable steps in'my improved lasting process, together with devices adjunctive thereafter, all by way of example and without limiting intent. In the drawing, i

Fig. 1 is a plan view of an adhesive leaf employed in the practice of my improved process;

Fig. 2 is a fragmentary plan view of the.

toe en d portion of a shoe, showing the application of one of my adhesive lasting leaves to theshoe prior to the final leveling of the upper material;

Fi 3 is a similar view, to smaller scale, showm the edge vof the upper vat the toe wiped inwardly over the adhesive leaf and secured by the adhesive to the insole;

Fig. 4: is a vertical section through a paratus useful in activating my improve ad hesive lasting leaves just prior to application tothe shoe bottom;

Fig. 5 is a fragmentary plan view of the devce oif Fig. 4 with the cover removed; v Fig. 6 is a vertical section substantially on the line 6 6 of Fig. 4;

Fig. 7 is a diagrammatic elevation, to small scale, partly in section, illustrating apparatus suitable for use in preparmgmy improved adhesive lasting leaves;

Fig. 8 is a plan view of a leaf strip consisting of leaves of a shape different from that shown in Fig. 1; and l Fig. 9 is a section, to large scale, on line 9-9 of Fig. l..

With the intended object in view, I employ a normally inactive adhesive which is furnished to the laster in the form of a/dryv sheet or film, the sheet material preferably being so prepared that portions of a size and shape suitable for use 1n an. individual shoe are readily available to the operator. I have sometimes referred to such individual portions as toe stamps, but since the invention is not in any sense necessarily limited to the lasting of the toe portion of the shoe, I prefer to refer to such individual portions of the adhesive material as lasting lleaves, such portions being flexible, thin, and leaf-like in character.

The lasting leaves lthus employed may consist of homogenous pieces of sheet adhesive of suitable character and normally stiff or at least strong enough to permit ready handling, and of'sufficient thickness and substance to furnish the requisite charge of adhesive for use in a shoe, or, if preferred, the adhesive film may be furnished in the form of a coating or an impregnant upon or within a sheet of a carrier material, for example, paper, cloth, or the like. In the latter case, it is preferred to perforate, make foraminate, or otherwise reduce the bulk of the carrier material in order to avoid adding undue bulk to the toe material of the shoe and, vmore important. to ensure a direct union of the meeting parts of the shoe by the cement rather thanthrough the interposed carrier material. The cement or adhesive employed may be of any suitable charac-i ter adapted to become adhesive through the application of solvent, heat, or both, and preferably setting very rapidly after incorporation in the shoe. Thus I may employ a cellulose derivative, for example cellulose nitrate, or a compound thereof, either in dry sheet form of homogeneou.s character or applied asa coating or impregnant to cloth, paper, or the like, and adapted to be made sticky by exposure to acetone or other solvent, either in liquid or vaporous form. Alternatively I may use Burgundy pitch, camar gum, or other thermoplastic cement, either in the form of homogeneous sheets, or coating or impregnating a suitable carrier material.

For convenience I prefer to prepare the adhesive material in the form of strips of proper width and incised in such a way as to facilitate tearing off` pieces of approximately the shape of the end ortion of the shoe, such pieces, as above re erred to, being hereinafter called lasting leaves.

In preparing my sheet adhesive, assuming for illustration that it is to consist of a carrier sheet coated or impregnated with the selected adhesive, I first preferably prepare long strips 5"L of the sheet material, which for convenience may be coiled-or rolled, and after drawing the strip through a bath of the adhesive, previously rendered fluid by solvent, heat or the like, I allow the strip to dry; then slit or perforate it at the proper points to form lines or areas of weakness to facilitate tearing oft' sections of the desired shape and then preferably reroll or fold it for use. Preferably )erforated sheet material is employed, an when this is drawn through the adhesive bath and dried, it has a surface coating C of adhesive (Fig. 9) together with uniformly distributed areas B consisting of homogeneous films of the adhesive adapted when in use directly to unite the opposed shoe parts between which the leaf is placed. Obviously for best results the perforations should form a large percent of the total area of the material, but this may be limited by the necessity of providing suflicient of the carrier material to furnish the desired strength and stiffness for handling. yIf desired and in order to save adhesive, the slitting operation, where by portions of the strip are usually removed in order to produce leaves of the proper shape, may be performed before running the sheet material through the adhesive bath, although if the carrier sheet be thin and easily broken, it may be desirable, as above described, to delay the slitting operation until after drying.

In using the novel adhesive inthe lasting operation the shoe upper l (Fig. 2) is first pulled over according to usual methods and the sides are lasted. The pulling-over tacks at the toe are then removed and, in accordance with a preferred method, the projecting margin of the lining is trimmed away substantially flush with the bottom of the inner sole at the toe, the edge of the toe box, if such be used, either being trimmed off at this time with the lining or, if left to project over the insole, being furnished with notches in its edge before assembly with the other parts, as more fully described in my prior application. The operator now wipes in the marginalportion 2 of the upper (and the toe cap, if the edge of the latter is to overlap the sole) by `means of the bed lasting wipers in usual fashion. The wiper plates are then withdrawn and lifted and, if desired, the central portion of the wipedin material may be shaved off. The operator now takes one of the previously prepared lasting leaves 3 (Figs. l and 2) which, if comprising a solvent adhesive, has just been activatedby the proper solvent to make it sticky, and introduces it between the inner sole 4 and the partially lasted overlying toe portion 2 of the upper. A heater plate (not shown) as described in my aforesaid application, may now be laid upon the pleated material of the upper at the toe, and the bed lasting wipers are lowered onto the edge of thez Aplate and left until the adhesive furnished by the lasting leaf 3 has been driven by the heatand pressure into the interstices of the opposed shoe materials and has set firmly enough to hold them in position when the pressure is removed. Usually it is sufficient to leave the parts in position under pressure while the operator is completing the heel lasting, which, if desired, may be accomplished in a similar fashion.

After the wiper plates are lifted and the heater removed, the marginal portions of the upper are firmly held in lasted position by the inter sed adhesive, whether the latter be in the orm of a homogeneous film, or consist of adhesive coatin or impregnating an interposed carrier. en the box toe {iange intervenes between the inner sole and the upper, its notches permit suflicient direct adhesion of the inner sole and upper or, if desired, lasting leaves may be introduced both below and above the boxy toe flange, thus providing additional strength.

xWhen a thermoplastic adhesive is used, the lasting leaf may be interposed between the l shoe parts in dry, non-adhesive condition and rendered active solely' by the warmth of the heater device. On the other hand, when a solvent adhesive is employed, I preferably make the lasting leaf active or stic immediately prior to its introduction into the shoe b the use of a suitable solvent as above descri ed. In accordance with one arrangement I pass the strip 5 (Fig. 5) of united lasting leaves through a chamber containing solvent, preferably wetting the strip with liquid solvent and then permitting it to stand or mull in an atmosphere of the solvent va or for a time suilicient to permit thoroug impregnation of the solvent without excessive surface wetting. Then when the lasting leaf is torn from the end of the strip, its'surface is not excessively sticky,

and it is still stiff enou h for read manipulation. Thus little, i any, of t e cement adheres tothe fingers of the user and dan er of daubing the exposed parts of the.' s oe upper is substantially eliminated.

In Fig. 7 I have diagrammatically indicated a desirable sequence of ste s in preparing the adhesive material. T us a carrier strip 58L of paper, cloth, or the like of predetermined width is conveniently fur- "nished in the form of a roll 6,- (the material preferably being foraminate or perforate) and the roll is mounted upon a suitable support 7 to facilitate unwinding. The material is pulled olf from the roll and drawn through a receptacle 8 containing the selected adhesive in liquid. form and after proper vcoating or impregation the material is caused to emerge from the receptacle and dried, either by exposure to the atmosphere alone or with the assistance of artificial currents of air or the like. After drying, the strip of material passes through a suitable device 9 operating to punch, cut or otherwise shape the individual leaves 3by the production of indentations, incisions, or the like,`defining lines of separation or weakness and/or areas of weakness in the material such as toldefine and to facilitate tearing oil' sections ofrproper shapen After this operation the material preferably 'is wound to form a roll ready for use by the laster.

In Fig. 5 one desirable form of strip is in dicated, the perforated sheet material having substantiall parallel edges 11 and 12, and at regular y spaced intervals having V-shaped incisions 13 merging into the curved incision 14 so ,as to leave openings 15 along the center line of the strip. The lateral ends of the incision 13 reach nearly to the edges 11 and 12 of the strip so that at the points 16 and 17 areas of weakness are formed, permitting successive sections of the strip to be torn olf easily. Thus by tearing the strip at the points 16 and 17, successive lasting leaves 3, as shown in Fig.l 1, result, the curved edge 148L of the leaf being adapted to fit into the toe portion of the shoe bottom, while theV-shaped notch 15a reduces the bulk of the material at the end of the shoe. In preparing the adhesive material as above describedthe surfaces of the strip are coated with the adhesive, and this adhesive extends across each ofthe perforations 18 in a continuous homogeneous film.

When the adhesive is of a nature requiring solvent to make it stick, I preferably furnish the laster with apparatus such as herein illustrated in Figs. 4, 5 and 6, or its equivalent, for preparing the leaves just prior to the lasting operation. This apparatus comprises a receptacle 19 adapted to hold a body of liquid solvent 20 and preferably having clamping means 21 and 22 .for attaching it firmly to a bench or other support. The receptacle preferably is furnished with a tight fitting cover 23, removably held in place, as by pins 24, engaging bayonet slots 25 in the edge of the cover. The receptacle has a window 26 at one end in which is arranged a guide roll 27 over which the coated strip 5 passes, being drawn oli'` from a properly supported supply roll, not shown. Preferably the cover of the receptacle has an opening through which `passes a vertically slidable rod 28 provided with a knob 29 at its upper end and normally heldin elevated position by a spring 30. Below the cover a guide sleeve 31 is secured to the rod 28, said sleeve having a passage for the strip 5 and being movable downwardly by depression of the knob to carry the strip 5 below the surface of the liquid solvent. Preferably the receptacle is provided with spaced guide partitions 31 dlsposed at opposite sides of the sleeve 31 and with a guide trough 31b extending upwardly from the bottom ofthe receptacle toward an exit opening 32 in the cover 23. The strip of material emerges through this openlng 32, after being activated `by the solvent, and to facilitate tearing oil' the forward leaf from the strip I preferably provlde the receptacle with an upstanding tear pin 33 projecting above the level of the cover just beyond the opening 32.

In using this apparatus the strip 5 passes through the opening 26, then through the sleeve 31 and then out through the opening 32. The operator depresses the knob 29 at suitable intervals so as to immerse the strip for a short time in the liquid solvent, but upon release of the knob the strip is raised to the position shown in full lines in Fig. 5. The receptacle is of a length substantially greater than that of a single lasting leaf so that a plurality of such leaves are always within the receptacle; and as the receptacle is substantially closed and as the solvent is usually volatile, thus providing an atmosphere heavily laden with fluid vapor above the liquid level, the leaves are subjected to a prolonged mulling action in this vapor atvlnosphere after their initial wetting with the solvent, thus ensuring their thorough impregnation by the solvent without unnecessarily softening the exterior surface of the leaf or rendering it too sticky or flabby for handling.

Assuming that the exposed end leaf of the strip has been properly activated and projects from the opening 32, the operator seizes this endmost leaf 3a (Fig. 5) between his thumb and nger, and by first drawing the strip forwardly and downwardly so that the pin 33 enters the foremost opening 15 and then pulling the end leaf 3EL sidewise, he can readily tear it from the strip without disturbing the other leaves forming the strip. The leaf thus removed is now ready for use in lasting. and is inserted in the toe bottom as above described.

In Fig. 8 I have shown a strip 5b particularly adapted for use at the heel end of the shoe, and it will be understood that strips of this general character, adapted to furnish leaves of any desired shape or size, may be prepared in accordance with the general directions above given and as circumstances may demand, and that the laster may be kept supplied with strips of such widths, leaf configurations, thickness, etc., as may be useful in lasting shoes of different styles or sizes, or opposite ends of the same shoe,

While I prefer to furnish these lasting leaves to the laster inthe form of a continuo us strip from which he can pull off successive sections as required, I contemplate the preparation of the lasting leaves as individual units which may be arranged in stacks or otherwise for convenient use and which may be activated in any desired manner prior to introduction into the shoe.

Moreover, while I have hereinabove referred to the use of a heater plate as ad- ]unctlve to the lasting operation and as useful in flattening the toe material and to facilitate the cementing operation, I contemplate that under some circumstances this heater may be dispensed with, the present invention being of broader scope and generally inclusive of the use of an adhesive lasting leaf of the type herein described and for the purposes mentioned.

Although certainspecific materials, modes of procedure, shapes of parts, etc., have been described as illustrative of the invention, I wish it to be understood that the invention is not thereby limited, but only as defined inthe appended claims.

I claim:

1. That method of lasting an end portion of a shoe which comprises as steps wiping in the marginal portion of the upper at said end by means of the wiper plates of a bed laster, retracting said plates, introducing a leaf of adhesive material between the insole and the wiped-in upper material at said end portion, and applying pressure b v means of the wipers sufiicient to level and set the wiped-in portion of the upper.

2. That method of lasting an end portion of a shoe which comprises as steps wiping in the marginal portion of the upper at said end by means of the wiper plates of a bed laster, retracting said plates, activating a leaf of adhesive material to cause it to become sticky, introducing said leaf of niaterial between the insole and the wiped-in upper material at the end portion of the shoe, subjecting the wiped-in material' lo heat and pressure to cause the adhesive to penetrate the insole and upper, and retaining the parts under pressure until the adhesive has set.

3. That method of lasting an end portion of a shoe which comprises as steps wiping in the marginal portion of the upper at 'said end by means of the wiper plates of a bed laster, retracting said plates, introducing a leaf of adhesive'material between the insole and the wiped-in upper material at said end portion, disposing a heater member upon the forepart of the shoe bottom, and bringing the wiper plates down upon said heater to cause the latter to level and set the wiped-in portion of the upper.

4. That method of lasting an end portion of a shoe which comprises as steps wiping in the marginal portion of the upper of the shoe at saidv end by means of the wiper plates of a bed lasting machine, retracting said plates from their'advanced posit1on, providing a portion of adhesive film in a form which may be handled, introducing said portion of adhesive film between the insole of the shoe and the wiped-in upper material at said end of the shoe, disposing a pressure member upon the wiped-in material, and holding said pressure member against said material and under pressure by means of the bed lasting wipers until the adhesive film has permanently united the insole and wiped-in upper material.

5. That method of lasting an end portion of a shoe which comprises as steps wiping in the marginal portion of the upper at said end of the shoe by means of the wiper plates of a bed lasting machine, retracting said plates, providing a lasting leaf comprising aA carrier sheet having a lm of adhesive thereon, introducing said leaf between the insole and the wiped-in upper material at said end ofthe shoe, disposing a pressure member upon the wiped-in material and holding said pressure member against said material and under pressure by means of the bed lasting wipers vuntil the film of adhesive has permanently united the insole and wiped-in upper material.

6. That method of lasting an end portion of a shoe which comprises as steps wiping in the marginal portion of the shoe upper at' said end of the shoe by means of the wiper plates of a bed lasting machine, retracting said plates, providing a lasting leaf comprising a perforated carrier sheet having an adhesive film extending across its perforations, introducing said leaf'betweenA the insole and the wiped-in upper material at said end of the shoe,dis'posing a pressure member upon the wiped-in material, and

viding a lasting leaf comprising a film of normally dry and nonsticky adhesive, ex-

posing the leaf to the action of a solvent for the adhesive, introducing said leaf between the insole and the wiped-in upper portion at said end of the shoe, placing a presser member upon the wiped-in material and exerting pressure upon said presser member by means ofV the lasting machine Wipers until the adhesive has set and permanently united the insole and wiped-in upper material. l

JACOB S. KAMBORIAN. 

